This research program will build on the progress of the Phase I study, where the production of uniformly stable isotopically-labeled L(+)-lactate was demonstrated. Utilization of algally derived feedstocks for the production of stable isotopically labeled compounds is a feasible option that can be made more economically viable by utilization of the biomass produced as a by-product. The Contractor shall develop economical production systems for six (6) uniformly isotopically labeled (UL) compounds: sodium lactate, sodium pyruvate, glutamic acid, glutamine, arginine and tryptophan. All of these biomolecules are of interest to the research and health care community and will be used as (1) invivo metabolic tracers and (2) for NMR protein structural elucidation studies using mammalian cell expression systems. The labeled compounds will be produced from microorganisms that use UL algal products (i.e., glucose and amino acids) as their sole organic nutrients. It is the goal of this project to make UL substrates available and affordable to meet present and future needs within the research community.